:root { 
    --billy-orange: #F5A623; 
    --billy-dark: #333; 
    --billy-blue: #008080; 
    --bg-light: #f9f9f9; 
    --slate-200: #e2e8f0;
    --slate-300: #cbd5e1;
    --slate-500: #64748b;
    --slate-700: #334155;
    --slate-800: #1e293b;
}

#billy-notes-wrapper {
    font-family: 'Segoe UI', 'Microsoft JhengHei', sans-serif;
    -webkit-font-smoothing: antialiased;
    color: #333; 
    line-height: 1.6;
}

#billy-notes-wrapper h1 { 
    color: var(--billy-blue); 
    border-bottom: 3px solid var(--billy-orange); 
    padding-bottom: 10px; 
    font-size: 2em; 
    text-align: center; 
    margin-bottom: 20px; 
    margin-top: 0; 
}
.zh-text { color: #666; font-size: 0.9em; display: block; margin-top: 4px; font-weight: normal; }

.note-card { 
    background: var(--bg-light); 
    border-radius: 12px; 
    padding: 0; 
    margin: 20px 0; 
    box-shadow: 0 4px 15px rgba(0,0,0,0.05); 
    border-top: 4px solid var(--billy-blue); 
    overflow: hidden;
}

.card-header {
    padding: 20px 25px;
    border-bottom: 1px solid var(--slate-200);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: #fff;
    gap: 15px;
}

.hud-display {
    text-align: center;
    width: 100%;
    padding: 15px;
    background: var(--bg-light);
    border-radius: 8px;
    border: 1px solid var(--slate-200);
    position: relative;
    overflow: hidden;
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
}
.hud-display::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px;
    background: linear-gradient(90deg, var(--billy-blue), var(--billy-orange));
}
.hud-val { font-size: 1.25rem; font-weight: bold; line-height: 1.2; }

.diagram-container {
    position: relative; width: 100%; background: #0f172a;
    border-bottom: 1px solid var(--slate-200); padding: 0;
    line-height: 0; aspect-ratio: 16/9; overflow: hidden;
}
canvas { display: block; width: 100%; height: 100%; }

.sliders-wrapper {
    padding: 25px; background: #fff; border-bottom: 1px solid var(--slate-200);
    display: grid; grid-template-columns: 1fr; gap: 20px;
}
@media (min-width: 640px) { .sliders-wrapper { grid-template-columns: 1fr 1fr; } }

.slider-group {
    display: flex; flex-direction: column; gap: 8px; padding: 15px;
    border-radius: 8px; background: var(--bg-light); border: 1px solid var(--slate-200);
}
.slider-group.source-a { border-left: 4px solid #3b82f6; }
.slider-group.source-b { border-left: 4px solid #ef4444; }

.slider-header { display: flex; justify-content: space-between; align-items: center; font-weight: bold; font-size: 0.9rem; color: var(--slate-800); }
.val-badge { background: #fff; border: 1px solid var(--slate-200); padding: 2px 6px; border-radius: 4px; font-family: monospace; font-size: 0.85rem; }

input[type=range] { -webkit-appearance: none; width: 100%; background: transparent; }
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none; height: 18px; width: 18px; border-radius: 50%;
    background: var(--billy-blue); cursor: pointer; margin-top: -6px; 
    box-shadow: 0 2px 4px rgba(0,0,0,0.2); border: 2px solid white;
}
.slider-a::-webkit-slider-thumb { background: #3b82f6 !important; }
.slider-b::-webkit-slider-thumb { background: #ef4444 !important; }
input[type=range]::-webkit-slider-runnable-track { width: 100%; height: 6px; cursor: pointer; background: var(--slate-200); border-radius: 3px; }

.controls { padding: 20px 25px; display: flex; flex-direction: column; gap: 15px; background: #fff; border-bottom: 1px solid var(--slate-200); }

.btn-primary {
    background: var(--billy-blue); color: white; padding: 10px 20px; border-radius: 8px;
    font-weight: bold; cursor: pointer; transition: all 0.2s; border: none;
    display: flex; align-items: center; justify-content: center; gap: 8px; flex: 1;
}
.btn-primary:hover { background: #006666; transform: translateY(-2px); }

.btn-secondary {
    background: white; border: 2px solid var(--slate-300); color: var(--slate-700);
    padding: 10px 20px; border-radius: 8px; font-weight: bold; cursor: pointer;
    transition: all 0.2s; display: flex; align-items: center; justify-content: center; gap: 8px;
}
.btn-secondary:hover { background: var(--bg-light); }

.toggle-btn {
    padding: 8px 12px; border-radius: 6px; font-size: 0.85rem; font-weight: bold;
    cursor: pointer; transition: all 0.2s; border: 2px solid transparent;
    display: flex; align-items: center; gap: 6px;
}
.toggle-a.active { background: #eff6ff; color: #1d4ed8; border-color: #bfdbfe; }
.toggle-b.active { background: #fef2f2; color: #b91c1c; border-color: #fecaca; }
.toggle-res.active { background: #faf5ff; color: #7e22ce; border-color: #e9d5ff; }
.toggle-btn.inactive { background: var(--bg-light); color: var(--slate-500); border-color: var(--slate-200); }